复合式衬砌让压支护下软岩大变形隧道应用效果对比分析  

Comparative Analysis of the Application Effect of Soft Rock Large Deformation Tunnel under Composite Lining Yielding Support

作　　者：杨文 YANG Wen(Sichuan Provincial Construction Engineering Quality and Safety Station,Chengdu 610047,China)

机构地区：[1]四川省建设工程质量安全总站,成都市610047

出　　处：《公路》2025年第4期477-483,共7页Highway

摘　　要：为对比研究复合式衬砌软岩隧道在让压支护及传统刚性支护下的应用效果,基于软岩公路隧道实体工程,分析刚性支护下软岩隧道围岩大变形的原因,采用有限元模拟建立三维模型,对比软岩隧道刚性支护和让压支护下初支和围岩变形以及钢拱架和初支应力差异,并在现场试验段应用验证让压支护的合理性。结果表明:让压钢管在荷载作用下拉伸变形吸收能量,适应围岩变形的同时提供足够的承载力;刚性支护和支护让压下围岩变形均以隧道延伸方向变形为主,让压支护下围岩X、Y方向变形分别较刚性支护增加12.3mm、9.1mm;让压支护下隧道初期支护变形大于刚性支护,两种支护方式下初支结构轴力最大值均在拱顶,但让压支护拱顶轴力较刚性支护下降约48%,且让压支护下的初支轴力及钢拱架应力分布均较刚性支护下更均匀;现场监测与数值仿真中台阶开挖围岩变形均最大,且中台阶收敛值最大相差35mm,钢拱架内外侧拱顶位置应力差值均不足10%,误差在合理范围内,两者均具有一定的可靠度。建议进一步对让压支护结构合理布设间距及位置等参数深入研究。In order to compare and study the application effect of composite lining soft rock tunnel under yield support and traditional rigid support,this paper analyzes the causes of large deformation of surrounding rock of soft rock tunnel under rigid support based on the solid project of soft rock highway tunnel.The three-dimensional model is established by finite element simulation,and the deformation of primary support and surrounding rock,the stress difference of steel arch and primary support under rigid support and yield support of soft rock tunnel are compared.The rationality of yield support is verified by application in field test section.The results show that the tensile deformation of yielding steel pipe absorbs energy under load,adapts to the deformation of surrounding rock and provides sufficient bearing capacity.The deformation of surrounding rock under rigid and yielding support is mainly in the direction of tunnel extension.The deformation of surrounding rock in X and Y directions under yielding support is 12.3 mm and 9.1 mm higher than that of rigid support respectively.The deformation of the initial support of the tunnel under the pressure support is greater than that of the rigid support.The maximum axial force of the initial support structure under the two support methods is in the vault,but the axial force of the pressure support vault is about 48%lower than that of the rigid support,and the axial force of the initial support and the stress distribution of the steel arch under the pressure support are more uniform than those under the rigid support.In the field monitoring and numerical simulation,the deformation of the surrounding rock of the step excavation is the largest,and the maximum difference of the convergence value of the middle step is 35 mm.The stress difference between the inner and outer vaults of the steel arch is less than 1o%,and the error is within a reasonable range.Both have certain reliability.It is suggested to further study the parameters such as the reasonable spacing and posit

关 键 词：软岩隧道 复合式衬砌 大变形 让压支护 刚性支护 数值仿真 

分 类 号：U455.91[建筑科学—桥梁与隧道工程]